Knowledge Core Collection:https://hdl.handle.net/11681/464282024-03-28T16:41:00Z2024-03-28T16:41:00ZPhotoelastic studies for vehicle mobility researchMellinger, Frank M.Hubbard, John H.Peters, R. L.https://hdl.handle.net/11681/469252024-03-27T13:02:55Z1965-08-01T00:00:00ZTitle: Photoelastic studies for vehicle mobility research
Authors: Mellinger, Frank M.; Hubbard, John H.; Peters, R. L.
Abstract: The test procedures and techniques developed in the studies reported herein provide a means of obtaining photoelastic stress patterns for moving wheel loads at controlled degrees of slip. Sufficient information was developed to compute normal and shear stress distribution on planes in the gelatin foundation within one-fourth inch of the contact surface between the moving wheel load and gelatin, if certain approximations are made. Further study is indicated to accurately define the stress at a point. Concerning the action of the static and moving wheel loads on the gelatin model, it was found that there was an increase in maximum shear
stress for the moving wheel load at 0, +25% and +50% slip over that of an equivalent static wheel load. This increase in maximum shear stress was due to a redistribution of normal stress at the wheel contact with the gelatin. Also, the maximum shear stress under the action of the moving wheel load was greater at 0 slip than at +25% and +50% slip.
Description: Contract Report1965-08-01T00:00:00ZA study of the vehicle ride dynamics aspect of ground mobility : Volume IV, field measurementsVan Deusen, Bruce D.Hoppe, C. H.https://hdl.handle.net/11681/469242023-04-22T09:02:01Z1965-04-01T00:00:00ZTitle: A study of the vehicle ride dynamics aspect of ground mobility : Volume IV, field measurements
Authors: Van Deusen, Bruce D.; Hoppe, C. H.
Abstract: The necessary terrain profile measurements for vehicle ride dynamics analysis are defined and the existing devices for profile measurement are evaluated in this context. The available analytical methods for classification and Interpretation of profiles are discussed and it is concluded that the power spectral density and amplitude distribution of profiles yield sufficient information for valid comparison. Methods for instrumenting vehicles for vibration measurements are discussed, with emphasis on data collection and analysis. Results of a field test feasibility study are reported. The test involved the analysis of vibration records from three military trucks and an attempt to measure profile from wheel spindle acceleration.
Description: Contract Report1965-04-01T00:00:00ZA study of the vehicle ride dynamics aspect of ground mobility : Volume III, theoretical dynamics aspects of vehicle systemsVan Deusen, Bruce D.https://hdl.handle.net/11681/469232023-04-22T09:01:51Z1965-04-01T00:00:00ZTitle: A study of the vehicle ride dynamics aspect of ground mobility : Volume III, theoretical dynamics aspects of vehicle systems
Authors: Van Deusen, Bruce D.
Abstract: One of the most important aspects of ground mobility is the problem associated with riding quality. Ride refers to the study and analysis of the vibratory motions of vehicles as excited by random terrain irregularities. The problems of interpreting vehicle motions in terms of human subjective response have been covered In Volume II. The problem of obtaining terrain measurements for study Is discussed in Volume IV. The present volume is intended to define the analytical techniques necessary to predict vibration in vehicles, emphasizing transfer function characteristics and the extension of transfer function techniques to non-linear analysis. Such statistics as the power spectral density and amplitude probability distribution are discussed. Two separate approaches to the problem are described, each with certain distinct advantages. The first approach is a digital computer oriented program for steady state response prediction of vehicle motion in terms of the frequency content. In this case, linear models of the vehicle may be evaluated and results pertain exclusively to the stable ground roughness problem. This implies operation of a vehicle over randomly spaced irregularities which are somewhat consistent in roughness. This approach to the problem is the simplest and yields results useful in evaluation of riding quality of vehicles over this type of terrain. The second approach to the problem is a direct prediction of the motion of vehicles in the time domain. The computation can be performed on either analog or digital computers, however the analog approach is stressed in this report. This approach is more definitive and will permit inclusion of non-linear aspects of the vehicle. The time domain approach can be extended to study of singular obstacles, deterministic inputs, or obstacle interference problems. This approach is more general, but it requires considerably more time to investigate a given vehicle configuration and requires a rather extensive analog computer facility for realistic vehicle models.
Description: Contract Report1965-04-01T00:00:00ZA study of the vehicle ride dynamics aspect of ground mobility : Volume II, human response to vehicle vibrationVan Deusen, Bruce D.https://hdl.handle.net/11681/469222023-04-22T09:08:59Z1965-03-01T00:00:00ZTitle: A study of the vehicle ride dynamics aspect of ground mobility : Volume II, human response to vehicle vibration
Authors: Van Deusen, Bruce D.
Abstract: This report sunmarizes the existing literature in the area of human response to vibration and interprets it in the vehicle environment context. Comparisons are made among the shake table approaches to determine human response to vibration as a function of frequency. Several examples of ride comfort studies in actual vehicle environment are also discussed. The problem of magnitude estimation is discussed in detail and both ratio judgement and cross-modality techniques are suggested as approaches. The first Appendix includes details of a feasibility study performed in the field to make ride measurements using the cross-modality technique. A second Appendix includes a research plan which is considered a sound next step in definition of human response to vehicle vibration in the cross-country environment.
Description: Contract Report1965-03-01T00:00:00Z